Motor fuel



nited Crystal Lake, lil., assignors to The Pure Oil Company, Chicago, 1111., a corporation of Ohio No Drawing. Application November 13', 1956 Serial No; 621,512 t 12 Claims. CI. 44-66) This invention relates to motor fuels and particularly motor fuels for use in spark-ignited, internal combustion engines. The invention is more particularly concerned with motor fuels containing a small amount of additive to mitigate the formation of deposits in the induction systems of automotive engines and to the methodfor inhibiting formation of such deposits.

Motor fuels containing tetraethyl lead have a tendency to deposit solid material in the induction system; that is, the area between the carburetor and combustion chamber 01' internal combustion engines, which interferes with the efi'icient operation of the engine. We have discovered that induction system deposits can be greatly mitigated by adding to the motor fuel or gasoline small amounts of certain types of additives.

An object of the invention is to provide an additive which when added to leaded motor fuel will lessen the tendency of the motor fuel to form deposits in the induction systems of internal combustion engines.

Another object of the invention is to provide a leaded motor fuel which Will not form deposits or which forms only small amounts of deposits in the induction system of an automotive engine of the internal combustion type.

A further. object of the invention is to provide a method for mitigating deposition in the induction system of internal combustion engines.

Other objects of the invention will make themselves manifest from the following detailed description of the invention.

We have discovered that partially esterified alkyl and alkylaryl glycosides when added to leaded motor fuel greatly mitigate the tendency of such fuels to form deposits in the induction system of spark ignition type internal combustion engines. These deposits tend to form in the area between the carburetor and the combustion chamber of the engine, particularly in the intake manifold and on the valves, causing constriction of the intake manifold and preventing proper closing of the valves, with resultant burning thereof. This tendency to form deposits is aggravated in connection with the use of modern fuels containing in addition to saturated hydrocarbons, unsaturated and aromatic hydrocarbons and tetraethyl lead.

We have found that by adding to such motor fuels glycoside esters of the type hereinbefore described in an amount between about 0.005 and by weight, induction system deposits can be eliminated or greatly reduced. We have found that the additive in the amount of about 0.01% by weight is effective for this purpose. This corresponds to about 35 pounds of glycoside ester per 1000 barrels of gasoline or similar motor fuel.

f tates Patent Patented Jan. 13, 1 959 2 v The glycosides useful in preparing the esters of our invention are represented by. the formula HOOH2CH(CHOH)2CHOR in which R is an alkyl or alkylaryl radical containing 1 to 12 carbon atoms and x is an integer of 1-8. These glycosides are esterified with 1 to 4 molecules of a monocarboxylic acid, such as fatty acids, aromatic acids and naphthenic acids, containing 8 to 24 carbon atoms per molecule. Mono, di, tri and' tetraesters of the glycosides are useful. However, the effectiveness of the additive in reducing deposit formation is dependent on the chain length of the esterifying acid and on the number of acid groups in the molecule. Shorter chains and less complete esterificatio'n produce esters which are more effective than those in which acids of longer chain lengths are used or more acid groups are attached to the glycoside by esterificat ion. the glycoside soluble in the gasoline in the amount in which it is added, a sufficient number of acidic groups or acidic groups of long enough chain length must be attached to the glycoside to make it soluble. The following groups of compounds and specific examples under each group are useful as additives for the purpose of our invention:

1. Hexoside mono esters in which R is an alkyl or alkaryl radical containing 1-12 carbon atoms and R is an aliphatic chain containing 7-23 carbon atoms.

Specific examples of compounds in this group are the mono-caprylate of methyl hexoside, mono-caprylate of lauryl hexoside, mono-caprylate of ethyl phenyl hexoside and the monocaprylate of propyl, butyl, amyl, hexyl, octyl, nonyl, decyl, and hexyl phenyl hexoside. ther examples are the mono-laurate, mono-palmitate, mono-stearate and mono-linoleate of the foregoing hexosides.

II. Di, tri and tetra esters of alkyl and alkylaryl hexosides However, since it is necessary to make in which R, R and R are defined the same as in II.

As a specific example where R is (CH R 'is C 'H and R is hydrogen, the compound is the monooleateof methyl tetroside. It will be apparent that any of the R groups under I can be substituted for R in Formula 111 and any fatty acid given under I can be substituted for oleic acid to give a corresponding tetroside ester;

IV. Pentoside esters I in which R, R and R are defined the same as in II.

Specific examples are trioleate of methyl pentoside and the mono and diesters of palmitic, stearic and linoleic acids in which the R group can be ethyl, ethyl phenyl or any of the specific alkyl or alkylaryl groups mentioned under II.

V. Other examples are the octoside esters such as the monooleate ester of ethyl octoside, and decoside esters such as the monooleate of ethyl decoside. As in the previous groups, the esters may contain one to four acid radicals and various alkyl and alkylaryl radicals can be substituted for the ethyl radical.

In order to demonstrate the invention, gasoline made by fluid catalytic cracking of petroleum oil was mixed with pounds of each of the glycoside esters listed in the following table, per 1000 barrels of gasoline. The gasoline used in these tests had the following characteristics:

Tetraethyl lead 3 cc./gal.

Each test run was conducted in a one-cylinder Lawson engine and the run lasted for a period of 12 hours.

Table I Percent Re- Run N0. Additive duction in Deposits none- (0.0894 gram) methyl glucoside trilaurate 78 methyl glucoside tetralaurate 52 methyl glucoside trioleate 49 methyl glucoside tetraoleate 39 Run A was made on the motor fuel without any glucoside ester added thereto to determine the magnitude of the deposit as a basis of comparison for the subsequent runs made with addition of the glucoside esters. Run B, in which the methyl glucoside trilaurate was used, produced the largest reduction in deposits. By comparing runs B, C, D and E, it will be seen that the glucoside which contained the shortest acid chain (laurate) and the glucoside which contained the fewest number of acid groups (trilaurate) gave the largest reduction in deposits. Similarly, the ester containing the longest and greatest number of acid groups (tetraoleate) gave the lowest reduction in deposits. All of the glucoside esters tested, however, gave a significant reduction in induction system deposits.

It will be apparent that to get the same effectiveness in deposit reduction it is neecssary to use a larger amount of glycoside ester when the acid radical is longer or more acid groups are attached to the glycoside than in the case where the acid radical is shorter or contains a lesser number of acid groups. The glycoside appears to be the active constituent of the ester in reducing deposits. The esterifying acid merely serves to solubilize the glycoside in the motor fuel.

Although in the specific examples fatty acids are used to esterify the glycoside, it will be understood that other acids, such as the aromatic and naphthenic acids having a sufficient number of carbon atoms to solubilize the resulting ester, can be used, such as toluic acid, cinnamic acid, phenyl propionic acid, and 2,2,6-trimethylcyclohexanecarboxylic acid.

We claim as our invention:

1. A hydrocarbon motor fuel of the gasoline boiling range containing about 0.005 to 5.0 wt. of esterified glycoside, said glycoside corresponding to the formula noonzontononnonon in which x is 1-8, R is from the group consisting of alkyl and alkylaryl radicals containing 1 to 12 carbon atoms, and the glycoside is esterified with one to four molecules of a monobasic aliphatic acid containing from 8 to 24 carbon atoms per molecule.

2. A motor fuel in accordance with claim 1 in which R is an alkyl group.

3. A motor fuel in accordance with claim 1 in which R is an alkylaryl group.

4. A motor fuel in accordance with claim 1 in which the esterified glucoside is a monoester of a fatty acid.

5. A motor fuel in accordance with claim 1 in which the ester is a triester present in the amount of about .005 to 5% by weight. I I

6. A motor fuel in accordance with claim 1 in which the ester is a tetraester.

7. A motor fuel in accordance with claim 4 in which the esterified glucoside is the monocaprylate.

8. A motor fuel in accordance with claim 4 in which the ester is the monocaprylate of lauryl hexoside.

9'. A motor fuel in accordance with claim 5 in which the ester is the trilaurate ester of methyl glucoside present in the amount of about .01%. i

10, A motor fuel in accordance with claim 5 inwhich 5' the ester is the trioleate of methyl glucoside present in the amount of about .01% by weight.

11. A motor fuel in accordance with-claim 6 in which the ester is the tetralaurate of methyl glucoside present in the amount of .01% by weight.

12. A motor fuel in accordance with claim 6 in which the ester is the tetraoleate of methyl glucoside present in the amount of .0l% by weight.

References Cited in the file of this patent UNITED STATES PATENTS FOREIGN PATENTS Great Britain May 30, 1956 

1. A HYDROCARBON MOTOR FUEL OF THE GASOLINE BOILING RANGE CONTAINING ABOUT 0.005 TO 5.0 WT. % OF ESTERIFIED GLYCOSIDE, SAID GLYCOSIDE CORRESPONDING TO THE FORMULA 